This invention relates to a apparatus for opening and closing a convertible top for an automotive vehicle.
This application is related to U.S. patent application Ser. No. 721,771, filed Apr. 10, 1985, now U.S. Pat. No. 4,664,436 entitled "Locking Device for an Automobille Top" by Wolfgang Eyb. The subject matter of that application, which is commonly owned with the present application, is hereby incorporated by reference into the present application.
In spite of all mechanical aids known in the present state of the art, opening and closing a manually operated convertible top is a cumbersome procedure. For example, during the opening step, the driver must first enter the vehicle and release the locking means for the top at the windshield frame; then he must alight again from the vehicle, fold back the top, and fix it in place. The desire for greater operating convenience and safer operation demands automation of the procedure.
German Unexamined Published Patent Application No. 1,925,227 discloses an apparatus for opening and closing the top of a convertible wherein the top is pivoted by means of an electric-hydraulic drive mechanism. Locking elements of this apparatus are designed so that they interrupt current to the electric-hydraulic drive mechanism until all locking elements have been released.
However, with this apparatus, the top still must be released and locked, respectively, by hand. There is no provision for turning off the electric-hydraulic drive mechanism once the final positions have been reached, so there exists the possibility of bending the top linkage out of shape. Furthermore, the disclosure mentions only an additional manual unit for securing the fully opened top in its position. Furthermore, hydraulic drive mechanisms require complicated systems for pressure monitoring and pressure regulation and no emergency operation is afforded. Finally, hydraulic drive mechanisms are expensive and difficult to maintain due to the almost unavoidable occurrence of leaks.
A convertible vehicle top having an electric drive unit is known from U.S. Pat. No. 2,770,489 wherein the top is pivoted by means of an electric motor and electro-magnetically releasable spring snap locks are used for locking the top in place. The pivoting mechanism is driven by means of several electric motors, the electric motors of the main drive means being synchronized with one another via flexible shafts and being provided with an auxiliary drive and an electromagnetic spring energy brake. The final or end positions of the pivoting mechanism are monitored by terminal position switches, the signals of which act on the control circuits of the relays which control the operation of the motors, the electromagnets of the brakes, and the locking mechanisms.
Although this arrangement eliminates the above-mentioned disadvantages, it does not provide for a signal acknowledging a completely performed locking or unlocking operation to the control unit and/or to the operator. Therefore, malfunctions occur, causing damage to the top mechanism. Moreover, the electrical control for this system is extremely complicated, fragile, cumbersome and expensive. Furthermore, it occupies a large amount of space.
Therefore, it is an object of this invention to provide a device for opening and closing a top for a motor vehicle, which device affords good operating convenience and effects the process of opening the top from the unlocking step to the complete unfolding, and the process of closing the top from swinging it closed to the full locking step, without any additional manipulation and solely by activating a single operating key, wherein all movements and conditions of the device are controlled and regulated so that damage to the device can be eliminated with a high degree of certainty. Furthermore, the device is simple and inexpensive to manufacture; it is easy to mount and adjust; and it is rugged, maintenance-free, and occupies a small amount of space.
These and other objects are attained in an apparatus for opening and closing a convertible top for a motor vehicle, which comprises an electric drive mechanism for operably moving the convertible top to fully open, fully closed, and intermediate positions, locking mechanisms located in a frame member of the top and cooperating with mountings in a windshield frame of the motor vehicle for locking the top in the fully closed position, and control circuitry for controlling the operation of the electric drive mechanism of the top and the locking mechanisms. The locking mechanisms preferably include an electric motor drive for moving the locks to fully locked and fully unlocked positions. The locking mechanisms further include position sensors for providing an indication of when the lock is in the fully locked, fully unlocked and intermediate positions. The control circuitry is connected to the electric drive mechanism of the top, the electric drive motor of the locking mechanisms and the position sensors. The control circuitry prevents operation of the top drive mechanism when the locking mechanisms are in a position other than the fully unlocked position.
The apparatus of the present invention further comprises limit switches located in proximity to the locking mechanisms and connected to the control circuitry, for providing a signal to the control circuitry when the top is in the fully closed position. The apparatus also includes a terminal switch for providing a signal to the control circuit when the top is in the fully open position. A manually operated key is provided for initiating locking and unlocking operations and closing and opening operations of the locking mechanisms and top, respectively.
The control circuitry includes a memory element for indicating a preceding locking or unlocking operation of the locking mechanisms. The control circuitry also includes processing means for processing signals from the manually operated key, the terminal switch, the limit switches, the position sensors and the memory element, and for producing control signals for controlling the operation of the top such that locking and unlocking of the locking mechanisms occur only when the top is in the fully closed position, and such that opening and closing of the top occurs only when the locking mechanisms are in the fully unlocked position. The control circuitry produces signals which interrupt the locking and unlocking operations when the fully locked and fully unlocked positions are reached, and which interrupt the opening and closing of the top when the fully opened and fully closed positions are reached. The operations of the top and locking mechanisms are interruptible and/or reversible by the operator at any time by means of the manually operated key.
A preferred embodiment of the control circuitry includes a logic circuit for processing the various signals to produce the control signals for operating the top drive and locking mechanisms. An alternative preferred embodiment includes a microprocessor for performing the functions of the logic circuit and, optionally, the functions of filter circuits and other components of a hard-wired control circuit.
The advantages primarily attained by this invention are that, by simple and economical means, a device has been created for opening and closing an automotive vehicle top, which entirely automates the process of opening and closing the top, permits safe operation without danger of damage, and moreover is rugged and service-free. By means of this device, a considerable improvement in operating convenience is achieved, and erroneous operations are prevented.